ESTUDIO DE UNA NUEVA ESPECIE DE LEVADURAS DEL GENERO TORULOPSIS BERLESE, AISLADAS DE LAS ESCAMAS DE LA PIEL HUMANA

Resumen

In this paper a new species of anascosporogenous yeast is described in the genus Torulopsis Berlese. lt is considered as  a new species under the name Torulopsis orbiculata n. sp. because in all cultures the cells show a very uniform circular shape. This yeast was isolaled in Tecomatlán, Pue., Mexico, from the scales of the skin of
patients suffering from "mal del pinto".
The fundamental characters of Torulopsis orbiculata n. sp. are :
1.-Culture in beer-wort: after 48 hours at 25° C. a small sediment appears, which in 20-30 days becomes very abundant and takes an avellanous color (Ridgway, Plate XL, 17'''-b; after 3 days a thin transparent ring is formed; after 5 days a mucous, humid and transparent veil begins to form and is completed in 25-30 days, with a granular surface and avellanous color. At the same temperature, after 48 hours, circular cells 4 to 6 micra in diameter are formed, either isolated or in pairs, with only one bud, granular protoplasm and abundant fat droplets.
2.-Culture in wort-agar: after 12 days at 25° C. circular colonies are formed, with smooth surface, convex elevation, entire borders, avellanous, brilliant, not translucid and of mucilaginous texture. After 48 hours at the same temperature cells are formed similar to those obtained in beer-wort.
3.-Streak culture: in wort-agar after 10 days at 25° C. colonies show an expanded form, with smooth or slightly undulated surface, convex elevation, finely undulated borders, vinaceous-buff in color (Ridgway, Plate XL, 17'''-d) brilliant and mucilaginous.
4.-Giant colonies: In wort-gelatin no giant colonies can be obtained because of the early liquefaction of the medium. In wort-agar a t 18°-20° C. after 40 days the giant colonies are circular and of avellanous color.
5.-Asci and ascospores: are not formed.
6.- Liquefaction of gelatin: results clearly positive; process begins after 3 days.
7.-Fermentation: does not ferment any sugar.
8.-Selectivity to sugars:
Dextrose   +                 Saccharose   +
Levulose    +                  Maltose        +
Manose      +                    Lactose       -
Galactose   -
9.-Assimilation of nitrogen:
Potassium nitrate      +      Peptone           +
Amonium sulphate    +      Asparagine      -
                                Urea   +
10.-Ethyl alcohol as substratum for development: unfavorable; even after 20 days development is scanty.